BIO 321 Endocrine System Questions
Peptide hormones are: A. synthesized by the ribosomes of endocrine cells. B. synthesized in the nucleus of endocrine cells. C. synthesized out of the amino acid tryptophan. D. the least prevalent type of hormone in the body. E. manufactured cooperatively by the mitochondria and smooth endoplasmic reticulum.
A
Which is TRUE regarding the structure and synthesis of hormones? A. Steroid hormones are synthesized from cholesterol. B. Thyroid hormones are catecholamines. C. The hormones of the adrenal cortex have the same structure as the neurotransmitters of adrenergic neurons. D. Most peptide hormones require binding proteins for transport in the blood. E. Vasopressin is synthesized in the posterior pituitary.
A
Which is most likely TRUE of an endocrine cell that contains an abundance of rough endoplasmic reticulum, a large Golgi apparatus, and secretory granules? A. It secretes a peptide/protein hormone. B. It secretes its product by diffusion through the lipid bilayer of the plasma membrane. C. It secretes by endocytosis. D. Its hormone product is synthesized from cholesterol. E. It secretes a hormone with a hydrophobic structure.
A
Which is most likely a result of hypersecretion of growth hormone? A. acromegaly B. dwarfism C. decreased plasma concentration of IGF-I D. decreased secretion of somatostatin E. increased secretion of growth hormone-releasing hormone (GHRH)
A
Which is part of the endocrine reponse to stress? A. increased secretion of corticotropin from the anterior pituitary B. increased secretion of corticotropin from the hypothalamus C. increased secretion of adrenocorticotropic hormone (ACTH) from the hypothalamus D. negative feedback to the adrenal cortex by adrenocorticotropic hormone (ACTH) E. decreased secretion of corticotropin-releasing hormone (CRH) by the hypothalamus
A
Which of the following is an action of the sympathetic nervous system during stress? A. It increases the ability to respond to situations where physical activity is required. B. It increases blood flow to the skeletal muscles and viscera. C. It inhibits blood clotting. D. It decreases ventilation of the lungs to save oxygen. E. It increases glycogen synthesis in the liver.
A
Which of the following statements about hormone actions is correct? A. Growth hormone is a tropic hormone for insulin-like growth factor 1. B. Inhibition of prolactin release by dopamine is an example of short-loop negative feedback. C. Somatostatin stimulates growth hormone secretion. D. ACTH inhibits cortisol secretion. E. Gonadotropin-releasing hormone (GnRH) stimulates growth hormone secretion.
A
Which of these describes secondary hypersecretion of hormone X? A. A growing tumor secretes hormone Y, which stimulates the gland that secretes hormone X. B. Cells of a growing tumor manufacture hormone X in unregulated fashion. C. Negative feedback from a tumor that hypersecretes hormone Z inhibits the gland that secretes hormone X. D. Hormone X is secreted by a growing tumor that is in the anterior pituitary gland. E. Hormone X is secreted in unregulated fashion by a tumor growing in a tissue that does not normally secrete hormone X.
A
Which would be the effect of a blood clot that blocked the vessels of the hypothalamo-pituitary portal system in the infundibulum between the hypothalamus and the anterior pituitary gland? A. secretion of adrenocorticotropic hormone (ACTH) would decrease and the adrenal cortex would atrophy B. secretion of gonadotropins will decrease and the gonads will hypertrophy C. secretion of corticotropin-releasing hormone (CRH) would decrease D. secretion of prolactin would decrease E. secretion of follicle-stimulating hormone (FSH) would increase
A
If a patient complains that she is feeling cold all the time and her clinical analysis shows that she has above normal levels of TSH, what does it mean? A. The patient has hypothyroidism. B. The patient has hyperthyroidism. C. The pituitary gland is not working right. D. She should get a better winter jacket; TSH has no relation with metabolic activity and body temperature.
A. The patient has hypothyroidism.
The role of hypothalamic inhibiting hormones at the pituitary gland is to oppose ______. A. hypothalamic releasing hormones B. hypothalamic activating hormones C. the function of neurosecretory neurons D. hypothalamic regulation of ADH secretion
A. hypothalamic releasing hormones
. Which of the following is TRUE regarding pituitary growth hormone (GH)? A. The liver produces a factor that mediates the metabolic actions of GH. B. GH stimulates insulin-like growth factor-1 (IGF-1) production by the liver and by many other cells. C. GH increases the sensitivity of tissues to the action of insulin. D. GH exerts negative feedback on its own production by inhibiting the hypothalamic secretion of somatostatin. E. IGF-1 stimulates the secretion of GH by anterior pituitary gland cells.
B
If the adrenal glands were removed from a patient, his plasma cortisol levels would ________, secretion of CRH by the __________________ would __________________, and secretion of ACTH by the ______________ would _____________. A. increase; hypothalamus; decrease; anterior pituitary gland; decrease B. decrease; hypothalamus; increase; adenohypophysis; increase C. decrease; anterior pituitary gland; increase; hypothalamus; increase D. increase; hypothalamus; increase; adenohypophysis; increase E. decrease; adenohypophysis; increase; anterior pituitary gland; increase
B
If the pituitary gland is removed from a human subject, which of the following is likely to occur? A. The adrenal gland will hypertrophy to increase cortisol production. B. The adrenal gland will atrophy and plasma cortisol levels will be reduced. C. The hypothalamus will secrete less CRH. D. The subject will remain euthyroid. E. There will be increased negative feedback on growth hormone by insulin-like growth factor 1 (IGF-1).
B
To synthesize thyroid hormones, iodine is attached to: A. cholesterol. B. the amino acid tyrosine. C. the amino acid tryptophan. D. acetyl coenzyme A. E. the amino acid phenylalanine.
B
Which accurately describes the median eminence of the hypothalamus? A. It is the site of synthesis of adrenocorticotropic hormone (ACTH). B. It is a site where neurohormones are release into blood vessels. C. It is the site where vasopressin is released into blood vessels. D. It is the stalk connecting the hypothalamus to the posterior pituitary. E. It is the main site where thyroid-stimulating hormone first enters the bloodstream.
B
Which correctly lists a function of estrogens in females and testosterone in males? A. They prevent the pubertal growth spurt. B. They are responsible for epiphyseal plate closure. C. They stimulate the secretion of gonadotropin-releasing hormone (GnRH). D. They stimulate the secretion of luteinizing hormone (LH). E. They stimulate the reabsorption of bone.
B
Which is NOT an effect of parathyroid hormone? A. increases the bone-degrading activity of osteoclasts B. decreases reabsorption of calcium by the kidneys C. promotes vitamin D synthesis, leading to increased intestinal absorption of calcium D. increases plasma [Ca2+] E. decreases reabsorption of phosphate by the kidneys
B
Which is a result of consuming a diet deficient in iodine? A. low plasma concentration of thyroid hormones due to reduced secretion of thyroid-stimulating hormone (TSH) by the pituitary gland B. low plasma concentration of thyroid hormones and an enlarged thyroid gland C. high plasma concentration of thyroid-stimulating hormone (TSH) due to a deficiency of thyrotropin-releasing hormone (TRH) D. high plasma concentration of thyroid hormones due to increased secretion of TSH by the pituitary gland E. low plasma concentration of thyroid hormones and atrophy of the thyroid gland due to reduced concentrations of thyroid-stimulating hormone (TSH)
B
Which is a result of elevated thyroid hormone levels? A. an increase in triglyceride storage B. increased Na+/K+ ATPase activity C. decreased body temperature D. mental lethargy
B
Which is most likely a characteristic of cells that secrete steroid hormones? A. They store large amounts of hormone. B. They are characterized by abundant smooth endoplasmic reticulum and few secretory granules. C. They contain large numbers of secretory granules. D. They are found in the anterior pituitary gland. E. They are found in the medulla of the adrenal gland.
B
Which of the following hormones is NOT usually secreted at higher levels in response to stress? A. aldosterone B. gonadotropins C. vasopressin D. antidiuretic hormone (ADH) E. beta-endorphin
B
Which of the following statements about hormones is correct? A. Anterior pituitary hormones are synthesized in the hypothalamus. B. All hormones secreted by the anterior and posterior pituitary glands are peptides. C. IGF-1 stimulates growth by increasing growth hormone secretion through positive feedback. D. All of the hypophysiotropic hormones are peptides. E. Only steroid hormones can regulate the secretion of steroid hormones.
B
Which of the following statements about oxytocin is TRUE? A. Target cells of oxytocin have receptors for the hormone in their nucleus. B. Oxytocin is synthesized in the hypothalamus. C. Oxytocin is secreted by the anterior pituitary gland. D. Oxytocin's main function is to increase the rate of respiration. E. Oxytocin keeps uterine smooth muscle from contracting, so it prolongs pregnancy.
B
Which of the hormones listed below has the most profound direct effect to stimulate the increased resorption of bone when plasma Ca2+ levels decrease? A. thyroxine B. parathyroid hormone C. calcitonin D. cortisol E. insulin
B
Which statement best describes the manner in which growth hormone stimulates cell proliferation? A. It directly stimulates cell division in most tissues. B. It stimulates the release of insulin-like growth factor I (IGF-1) from the liver and other target tissues of growth hormone. C. It stimulates metabolism. D. It stimulates the release of eicosanoids from lymphoid tissues. E. It stimulates sleep.
B
Which stimulates the secretion of growth hormone? A. waking from sleep B. exercise C. increased levels of IGF-I in blood D. high plasma glucose E. increased somatostatin secretion
B
What is the relation between triiodothyronine (T3) and tetraiodothyronine (T4)? A. Triiodothyronine (T3) is an inactive thyroid hormone that can be converted to tetraiodothyronine (T4), which is the active form of thyroid hormone. B. Tetraiodothyronine (T4) is an inactive thyroid hormone that can be converted to Triiodothyronine (T3), which is the active form of thyroid hormone. C. They are two different forms of thyroid hormones, with T4 being more active than T3. D. They are two different forms of thyroid hormones, with T4 opposing the action of T3.
B. Tetraiodothyronine (T4) is an inactive thyroid hormone that can be converted to Triiodothyronine (T3), which is the active form of thyroid hormone.
A patient goes to her doctor, complaining of fatigue, weight gain, and intolerance to cold. She also has a noticeable goiter in her neck. Which of the following is a most likely diagnosis and cause? A. She has hypothyroidism, possibly due to destruction of thyrotrope cells of her anterior pituitary gland. B. She has hyperthyroidism, possibly due to Graves' disease. C. She has hypothyroidism, possibly due to low iodine in her diet. D. She has hyperthyroidism, possibly due to a hypersecreting tumor of the anterior pituitary gland.
C
Acting alone, epinephrine and thyroid hormone each stimulates release of only a small amount of fatty acids from adipose cells. In the presence of thyroid hormone, epinephrine causes a much more substantial release of fatty acids from the cells. What is the term describing the effect of thyroid hormone on epinephrine's actions? A. antagonistic B. agonistic C. permissive D. direct E. paracrine
C
At what time in the lifespan is growth hormone secretion rate highest? A. in utero B. during childhood C. during adolescence D. during adulthood E. during senescence
C
Deficiency of iodine in the diet results in _____________ caused by ________________. A. a goiter; increased production of thyroid-stimulating hormone (TSH) and increased thyroid hormone levels B. atrophy of the thyroid gland; loss of negative feedback by thyroid hormones and increased thyroid-stimulating hormone (TSH) levels C. a goiter; loss of negative feedback by thyroid hormones and increased thyroid-stimulating hormone (TSH) levels D. atrophy of the thyroid gland; decreased sensitivity of receptors for thyroid-stimulating hormone (TSH) E. atrophy of the anterior pituitary gland; loss of negative feedback by thyroid hormones
C
Short-loop negative feedback occurs when hormones from the ______________ inhibit hormone secretion by the ______________. A. hypothalamus; anterior pituitary B. adrenal cortex; hypothalamus C. anterior pituitary; hypothalamus D. adrenal cortex; anterior pituitary E. anterior pituitary; adrenal cortex
C
What is the definition of a prohormone? A. Hormones that bind to endocrine glands and stimulate the secretion of a second hormone. B. Hormones that bind to endocrine glands and inhibit the secretion of a second hormone. C. A longer protein or peptide that is cleaved into shorter ones, at least one of which is a peptide or protein hormone. D. Hormones that stimulate the expression of receptors for a second hormone, promoting their action. E. Steroid hormones that are inactivated by having hydroxyl groups removed from their structure.
C
What term describes hormones secreted by the hypothalamus that regulate the secretion of hormones from the anterior pituitary gland? A. growth factors B. paracrine factors C. hypophysiotropic hormones D. metabotrobic-releasing factors E. cerebrovitalistic hormones
C
What term describes hormones that influence the secretion of other hormones? A. mineralocorticoids B. trophic C. tropic D. allosteric E. teratogen
C
Which does NOT apply to hormones? A. They are chemical regulators that are conveyed from one organ to another via the bloodstream. B. In some cases, the same chemical substances can also function as local regulators and/or neurotransmitters. C. All hormones are derived from cholesterol. D. They are secreted into the blood by ductless glands. E. They are sometimes secreted by neural tissue.
C
Which is a result of an absence of thyroid hormones during fetal development? A. acromegaly B. Cushing's syndrome C. congenital hypothyroidism (cretinism) D. Graves' disease E. Addison's disease
C
Which is an accurate description of the posterior pituitary and its functions? A. It is glandular tissue and secretes vasopressin and prolactin. B. It is neural tissue and is stimulated to secrete oxytocin and vasopressin by hypophysiotropic hormones. C. It is neural tissue, and vesicles containing oxytocin and vasopressin are transported to axon terminals there. D. It is glandular tissue and releases oxytocin and somatostatin when action potentials arrive along axons from the hypothalamus. E. It is neural tissue that secretes hypophysiotropic hormones that control the secretion of the anterior pituitary hormones.
C
Which of the following is NOT stimulated by cortisol during stress? A. gluconeogenesis B. protein catabolism C. glucose uptake into muscle cells D. triglyceride catabolism in adipose cells E. decreased sensitivity to insulin
C
Which would result from a vitamin D deficiency? A. hypercalcemia B. an increase in bone mass C. an increase in parathyroid hormone levels D. increased intestinal absorption of calcium
C
How could the hypothalamus affect glucose metabolism? A. By inducing the pituitary gland to produce Insulin Stimulating Hormone, which in turn increases production of insulin in the pancreas. B. By inducing the pituitary gland to produce Glucocorticotropic hormone (GH) C. By inducing the pituitary gland to produce adrenocorticotropic hormone, which in turn increases production of glucocorticoids at the adrenal cortex. D. The hypothalamus could never affect glucose metabolism.
C. By inducing the pituitary gland to produce adrenocorticotropic hormone, which in turn increases production of glucocorticoids at the adrenal cortex.
A cell may respond to the presence of insulin only if _______. A. it has enough cAMP B. it has nuclear insulin receptors C. it has insulin receptors at the plasma membrane D. it is a muscle fiber or a hepatocyte
C. it has insulin receptors at the plasma membrane
How is the concentration of a hormone in plasma determined? A. only by its rate of secretion B. by the number of its target cells in the body C. only by its rate of synthesis D. by its secretion and clearance rates, and whether or not it binds to carriers and/or other plasma proteins E. only by the rate of its degradation by the liver and kidneys
D
In what form is the body's largest pool of calcium? A. embedded in collagen in many types of connective tissue B. blood, dissolved within the plasma C. skeletal muscle, stored in terminal cisternae D. bones, in the form of hydroxyapatites E. liver, inside the endoplasmic reticulum
D
What is a main difference between the modes of action of peptide hormones and steroid hormones? A. Peptide hormones bind to intracellular receptors, whereas steroid hormones bind to receptors on the cell surface. B. Peptide hormones act as second messengers, whereas steroid hormones bind to receptors in the cytosol. C. Peptide hormones bind to receptors on the cell surface, whereas steroid hormones act as second messengers. D. Peptide hormones bind to receptors on the cell surface, whereas steroid hormones bind to intracellular receptors. E. There are no differences; both act by binding to intracellular receptors.
D
What would be the effect of a thyroid deficiency beginning in infancy? A. Gigantism would occur. B. Acromegaly would occur. C. Growth rate would be faster than normal. D. Growth rate would be slower than normal. E. Body temperature would be above normal.
D
Which is TRUE about hormone binding to the proteins found in plasma? A. Steroid hormones do not bind to plasma proteins. B. The binding proteins that transport hormones are hormones themselves. C. The tighter that a hormone binds to a carrier protein in the plasma, the faster the body can usually get rid of that hormone. D. Hydrophobic hormones like steroid and thyroid hormones need binding proteins because they are not very soluble in the blood plasma. E. Only peptide-type hormones can bind to the carrier proteins found in the plasma.
D
Which is a characteristic of hydrophobic hormones? A. They mostly bind to receptor proteins in the surface membrane of target cells. B. They are generally polar molecules. C. They usually have very rapid effects on target cells. D. Their mechanism of action generally involves altering protein synthesis. E. They are highly soluble in blood plasma.
D
Which is a function of the gonadotropic hormones? A. stimulating the release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) B. inhibiting the release of growth hormone C. inhibiting the release of prolactin D. inducing the secretion of steroid hormones by the gonads in both males and females E. stimulating the release of gonadotropin-releasing hormone (GnRH)
D
Which of the following hormones is NOT secreted by the anterior pituitary gland? A. somatotropin B. prolactin C. corticotropin D. erythropoietin E. thyroid-stimulating hormone (TSH)
D
Which of the following statements about hormone synthesis is NOT correct? A. Progesterone can be a precursor of cortisol. B. Progesterone is a precursor of mineralocorticoid and glucocorticoid hormones. C. Pregnenolone is a precursor for all steroid hormones. D. Tryptophan is a precursor for thyroid hormones. E. Peptide hormones are polymers of amino acids.
D
Kidney cells respond to vasopressin (or ADH) by means of a G-protein and PKC mediated mechanism. How would a cell's response to vasopressin be affected if the extracellular calcium concentration was reduced to 0.5 mM? A. The cells would no longer respond to vasopressin B. Response to vasopressin would be unaffected C. Response to vasopressin would be much faster D. Response to vasopressin would be significantly weakened
D. Response to vasopressin would be significantly weakened
What is the role of the parathyroid gland in the negative feed-back loop that regulates plasma calcium concentration? A. The parathyroid gland is the effector, because it restores the normal concentration of calcium in plasma. B. The parathyroid gland is the receptor, because it can sense when calcium in plasma goes below the normal value. C. The parathyroid gland is the control center, because it sends the message (PTH) that tells the effectors to conserve (kidney), to absorb (small intestine) or to release calcium (bone) into the plasma. D. The parathyroid gland is acting as both receptor and control center.
D. The parathyroid gland is acting as both receptor and control center.
What is a portal venous system? A. Veins that carry hormones B. A capillary bed that carry hormones C. A capillary bed within a gland D. Two capillary beds placed in series and connected by veins, known as portal veins.
D. Two capillary beds placed in series and connected by veins, known as portal veins.
A prohormone will become a hormone once _______. A. it detaches from its carrier protein B. it binds to a carrier protein C. it is inactivated D. it is chemically modified
D. it is chemically modified
. Which of the following is NOT true of pituitary growth hormone? A. It directly promotes protein anabolism in many cells. B. It causes differentiation of precursor cells that then respond to IGF-I by proliferating. C. Hypersecretion of growth hormone in adults leads to acromegaly. D. It is absent or deficient in pituitary dwarfs. E. It is necessary for fetal growth.
E
A deficiency in dietary iodine can cause: A. congenital hypothyroidism (cretinism). B. a slowing of mental functions. C. a low metabolic rate. D. a goiter. E. All of the choices are correct.
E
A hormone may be... A. inactivated by its target cell. B. activated by its target cell. C. inactivated by nontarget cells. D. excreted before it has a chance to act on a target cell. E. All of the choices could be correct.
E
A patient appears in a clinic complaining of irritability and chronic sweatiness. He also has a lump in his neck near his larynx. Blood tests show he has low levels of thyroid-stimulating hormone (TSH) in his plasma. Which of the following is the most likely diagnosis? A. primary hypothyroidism B. an iodine-insufficient diet C. secondary hypothyroidism D. hyposecretion of TRH E. Graves' disease
E
What is the major hormone responsible for mediating the body's general response to stress? A. thyroid hormone B. growth hormone C. testosterone D. aldosterone E. cortisol
E
Which are hormones secreted by the posterior pituitary? A. vasopressin and dopamine B. corticotropin and dopamine C. oxytocin and prolactin D. vasopressin and corticotropin E. antidiuretic hormone (ADH) and oxytocin
E
Which is NOT an endocrine function performed by the liver? A. secreting insulin-like growth factor 1 B. clearing hormones from plasma C. secreting angiotensinogen D. producing plasma proteins that bind hormones E. secreting insulin
E
Which is NOT true about receptors for steroid hormones? A. They may be proteins found in the nucleus. B. They undergo allosteric modulation when they bind to the hormone. C. They regulate gene transcription. D. They may be found in the nucleus. E. They are synthesized from cholesterol.
E
Which is a hormonal response to a stressful situation? A. Negative feedback from cortisol increases secretion of adrenocorticotropic hormone (ACTH). B. Secretion of aldosterone by the adrenal gland is decreased. C. Negative feedback from cortisol increases the secretion of corticotropin-releasing hormone (CRH). D. Plasma levels of adrenocorticotropic hormone (ACTH) decrease. E. Plasma levels of cortisol increase.
E
Which is true about the growth of long bones? A. Osteoblasts dissolve bone tissue when bones remodel in response to sex hormones. B. Osteoclasts are responsible for depositing new bone tissue at the epiphyseal growth plate before puberty. C. Before adolescence, bones are completely made up of cartilage; after puberty they ossify and harden. D. Growth in length occurs at a single epiphyseal growth plate in the center of the shaft of long bones. E. Growth in length occurs at two epiphyseal growth plates near the ends of long bones.
E
Which of the following statements is NOT true of the endocrine system? A. It is one of two major regulatory systems of the body. B. It is composed of glands that secrete chemical messengers into the blood. C. It is an important regulator of homeostatic mechanisms. D. It influences and is influenced by the nervous system. E. Most of its components are anatomically connected, like most other systems of the body.
E
Which of these could be a cause of hypertrophy of the adrenal cortex? A. autoimmune destruction of receptors for adrenocorticotropic hormone (ACTH) B. autoimmune destruction of hypothalamic cells that secrete corticotropin-releasing hormone C. injection of an excess of cortisol D. destruction of the anterior pituitary by a stroke E. excessively rapid clearance of cortisol from the circulation
E
Which would most directly decrease the production of aldosterone? A. going on a low-salt diet B. ingesting extra dietary vitamin D C. reducing dietary tyrosine D. increasing dietary cholesterol E. injecting a drug that blocks the production of angiotensin II
E